try multi-arch docker

flake.nix

@@ -2,14 +2,20 @@
   inputs = {
     nixpkgs.url = "nixpkgs/release-23.11";
     utils.url = "github:numtide/flake-utils";
+    flocken = {
+      url = "github:mirkolenz/flocken/v2";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
   };
 
   outputs = {
     self,
     nixpkgs,
     utils,
+    flocken,
   }:
     utils.lib.eachDefaultSystem (system: let
+      inherit (builtins) getEnv;
       overlays = [
         (import ./overlay.nix)
       ];
@@ -22,11 +28,26 @@
       nodeLd = pkgs.writeShellScriptBin "node" ''
         LD=$CC ${pkgs.nodejs_20}/bin/node $@
       '';
+      inherit (flocken.legacyPackages.${system}) mkDockerManifest;
     in rec {
       packages = rec {
         inherit (pkgs) demostf-api demostf-api-docker demostf-parser;
         docker = demostf-api-docker;
         default = demostf-api;
+
+        dockerManifest = mkDockerManifest {
+          tags = ["latest"];
+          registries = {
+            "docker.io" = {
+              enable = true;
+              repo = "demostf/api";
+              username = "$DOCKERHUB_USERNAME";
+              password = "$DOCKERHUB_TOKEN";
+            };
+          };
+          version = "1.0.0";
+          images = with self.packages; [x86_64-linux.demostf-api-docker aarch64-linux.demostf-api-docker];
+        };
       };
       devShells.default = pkgs.mkShell {
         nativeBuildInputs = with pkgs; [